(1) The synthesis of polypeptides on polymeric supports pioneered by Merrifield requires that each of the successive reactions proceed virtually to completion. It is, therefore, desirable to study the dispersion of the reaction rate constant characterizing reactive sites on a cross-linked polymer as a function of the variables of the polymer network structure. This can be accomplished if the quenching of the fluorescence of a group attached to the cross-linked polymer can be followed quantitatively. We plan to use for this purpose reflectance fluorescence of p-aminobenzoic acid groups, which is quenched by acylation. (2) In a paper by Kiefer et al., it was claimed that poly(ethylene imine) acylated with long chain fatty acids and carrying imidazole substituents was 10 to the l2th power times as efficient as imidazole in catalyzing the hydrolysis of nitrocatechol sulfate. The magnitude of this effect has not been satisfactorily explained and we plan to synthesize a series of polymers of this type with different contents of hydrophobic and imidazole substituents to obtain insight into this type of catalysis. (3) We plan to expand our studies of the solvent-dependence of the stereoselectivity of asymmetric reactions to the bromide displacement from a variety of alpha-bromophenylacetic esters by derivatives of proline, N-alkyl-prolines and derivatives of 2-carboxypiperidine. We shall also continue a search for an asymmetric nucleophile which would exhibit stereoselectivity in catalyzing the hydrolysis of p-nitrophenyl mandelate. BIBLIOGRAPHIC REFERENCE: H. Morawetz. Linear and Cross-Linked Polymers as Chemical Reagents. "Peptides: Chemistry, Structure and Biology", R. Walter and J. Meienhofer, eds., Ann Arbor Science Publ., 1975, p. 385.